Alkylglucosides are known substances. They correspond to the general formul a EQU R--O--G!.sub.p
in which R is derived from a fatty alcohol radical and G is the glucose radical. One or more glucose radicals can be bonded to a fatty alcohol radical, which results in an average degree of oligomerization p over the glucose units. The terms alkyl polyglucoside and alkyl oligoglucoside are therefore also used for this group of products in the literature.
Alkylglucosides are important nonionic surfactants which, as a result of their good detergent properties and high environment-friendliness, have found use to an ever greater extent in washing, rinsing and cleaning compositions.
For this purpose, it is necessary to have available and to store alkylglucosides over certain periods of time, for example as aqueous solutions or pastes, until final processing takes place. However, since aqueous alkylglucosides show a marked tendency toward crystallization, agglomerates which contain water of crystallization and greatly reduce the pumpability of the products are formed in the course of time during storage under ambient conditions.
These problems occur in particular with alkylglucosides in which the alkyl radical has 12 or more C atoms and with commercially available alkylglucoside mixtures in which the higher-chain content is correspondingly high and contains alkyl radicals having 12 or more C atoms to the extent of more than 50%.
Alkylglucosides are therefore usually stored not at room temperature but at temperatures of at least 35.degree. C. Although crystallization of the formulations can be largely prevented in this manner, storage at elevated temperature is associated with additional expenditure and can furthermore severely impair the color quality of the products.
To improve the resistance to crystallization, DE-A-42 25 224 proposes the addition of a number of "crystallization moderators", such as, for example, alkyl oligoglycosides based on short-chain alcohols, polyethylene glycol or iron (III) ions, but these have the disadvantage that they impair the surfactant properties or the color.
It is thus an object of the present invention to discover a concentrated surfactant composition based on alkylglucosides, with which storage of the glucosides at temperatures below 35.degree. C. is possible without the pumpability of the products being impaired by formation of crystalline agglomerates.